Ed Stewart worked on the pirate station Radio London in the mid-1960s and when that was closed down he took over from Leslie Crowther on Junior Choice in 1968.
Photograph: ITV/Rex/Shutterstock

Ed “Stewpot” Stewart, who has died aged 74 following a stroke, became a disc jockey in the days when hosting a BBC Radio 1 show virtually guaranteed both celebrity status and spin-off fame on television. He attracted as many as 17 million listeners with the weekend request programme Junior Choice – also broadcast on Radio 2 – during a 12-year run (1968-79). Stewart will be remembered for his bright and breezy style, ushered in by the jaunty theme tune Morningtown Ride.

He recorded interviews for the show with young patients in hospitals and recalled how his trademark jingle of a chuckling child was born out of such a trip: “This eight-year-old boy who had been pulling at my shirt all day piped up and, with an infectious laugh, said, ‘’Ello, darlin’!’ It was so spontaneous, and I’ve played it ever since because everyone asks to hear him.” Another defining element of Junior Choice during Stewart’s years on it were the novelty singles he championed, many for a new generation, including Max Bygraves’s You’re a Pink Toothbrush, Terry Scott’s My Brother, Clive Dunn’s Grandad, Mandy Miller’s Nellie the Elephant and Benny Hill’s Ernie (The Fastest Milkman in the West).

He joined the television chart show Top of the Pops in 1971. Alongside his own small-screen programmes, he had a seven-year run (1973-79) as presenter of Crackerjack, a bedrock of children’s tele- vision, mixing variety acts with party games and the hosts’ own sketches. “It’s Friday, it’s five o’clock, it’s Crackerjack,” he announced at the beginning, closing with his radio sign-off, “By-ee!”

Stewart was born in Exmouth, Devon, the son of Ray Mainwaring, a Treasury solicitor, and his wife, Peggy (nee Fraser). He was brought up in Wimbledon, south-west London, attended St Edward’s school, Oxford, and played the double bass in a jazz trio. When one of the group was doing national service in Hong Kong, in 1961 he invited Stewart to join him and a pianist there for a gig. Arriving to find it had been cancelled after the two others had been posted to Aden at short notice, he stayed and landed work with Radio Hong Kong as an announcer, film critic and rugby commentator under his real name, Ed Mainwaring. He later added the job of disc jockey to his duties.

In 1965, he returned to Britain, used his middle name to become Ed Stewart, and joined Radio London, one of the pirate ships operating legally from international waters to satisfy the thirst of a new generation for pop music that was not catered for by the BBC. Based four miles offshore, Radio London numbered among its DJs Tony Blackburn, John Peel, Kenny Everett and Dave Cash, who gave him the nickname “Stewpot”.

They left their North Sea ship for Radio 1 when pirate stations were banned by the Marine Broadcasting Offences Act 1967 and the BBC launched Britain’s first pop music station on 30 September that year. Stewart started by presenting Happening Sunday, which included listeners’ requests and the record reviews show What’s New.

Then, in February 1968, he replaced Leslie Crowther on Junior Choice, broadcast on Saturdays and Sundays. That year, credited as Stewpot and Save the Children Fund Choir, he recorded a charity single, I Like My Toys. On leaving the show, Stewart presented his own afternoon programme on Radio 2 from 1980. Stewpot (1970-71), his ITV children’s show, featured mainstream pop acts of the day such as Pickettywitch, the Scaffold, the New Seekers, Marmalade, Blue Mink and Leapy Lee. It was followed by Play It Again, Stewpot (1974), with pop stars and puppets. He was partnered by a rebellious robot in the BBC’s Ed and Zed! (1970).

Stewart’s celebrity brought him plenty of guest appearances in other television shows such as The Golden Shot (1973), Bruce’s Big Night (1978), Star Games (1979-80), Family Fortunes (1981) and Punchlines (1983-84). He was even ringmaster for broadcasts of Chipperfield’s Circus (1973-75), and the children’s magazine Look-In featured the star in its Stewpot’s Look-Out and Stewpot’s Newsdesk articles in the 70s.

Dropped by Radio 2 in 1983, he joined the newly launched commercial station Radio Mercury (1984-90), broadcasting to West Sussex and Surrey. He was invited to rejoin Radio 2 in 1991 and hosted a Saturday afternoon programme before returning to weekday afternoons, then Sunday evenings. In 1995, he broadcast live from the summits of both Ben Nevis and Snowdon, in aid of the Cystic Fibrosis Trust.

Stewart left in 2006 when his contract was not renewed, but he was so associated with Junior Choice that, from 2007, when Radio 2 was celebrating its 40th birthday, he hosted the station’s Christmas special of the show. It became an annual ritual, his last being broadcast on Christmas Day 2015. Tracks included Bernard Cribbins’s Right Said Fred, Peter, Paul and Mary’s Puff the Magic Dragon, and the Seekers’ recording of his trademark Morningtown Ride.

In his last 10 years, Stewart also stood in for DJs on the stations Big L, Classic Gold, KCFM, Wight FM and Spectrum FM in Spain, where he had a holiday home.

Out of the Stewpot, his autobiography, was published in 2005. He played in show business football teams and was a lifelong Everton fan. He began supporting the team in 1948 after feeling sorry on seeing them beaten 6-0 by Chelsea, the team his brother supported, at Stamford Bridge.

Stewart is survived by a son, Mario, and a daughter, Francesca, from his marriage to Chiara Henney, which ended in divorce.

• Edward Stewart Mainwaring, radio and television presenter, born 23 April 1941; died 9 January 2016